The shimano bb71is a complete xt level press fit bottom bracket assembly for shimano hollowtech ii mtb cranks the cups are made from fibre reinforced polymer material which reduces the risk of frame noise and damage shimano are a japanese born company with over 80 years39 experience of producing high quality bike components they are one of the largest cycling part manufacturers in the world so you can be confident in your purchase all shimano products come with two year warranty as stand